The Multifaceted Roles of Autophagy in Infectious, Obstructive, and Malignant Airway Diseases

Autophagy is a highly conserved dynamic process by which cells deliver their contents to lysosomes for degradation, thus ensuring cell homeostasis. In response to environmental stress, the induction of autophagy is crucial for cell survival. The dysregulation of this degradative process has been implicated in a wide range of pathologies, including lung diseases, representing a relevant potential target with significant clinical outcomes. During lung disease progression and infections, autophagy may exert both protective and harmful effects on cells. In this review, we will explore the implications of autophagy and its selective forms in several lung infections, such as SARS-CoV-2, Respiratory Syncytial Virus (RSV) and Mycobacterium tuberculosis (Mtb) infections, and different lung diseases such as Cystic Fibrosis (CF), Chronic Obstructive Pulmonary Disease (COPD), and Malignant Mesothelioma (MM)

Mitophagy in Cardiovascular Diseases

Cardiovascular diseases are one of the leading causes of death. Increasing evidence has shown that pharmacological or genetic targeting of mitochondria can ameliorate each stage of these pathologies, which are strongly associated with mitochondrial dysfunction. Removal of inefficient and dysfunctional mitochondria through the process of mitophagy has been reported to be essential for meeting the energetic requirements and maintaining the biochemical homeostasis of cells. This process is useful for counteracting the negative phenotypic changes that occur during cardiovascular diseases, and understanding the molecular players involved might be crucial for the development of potential therapies. Here, we summarize the current knowledge on mitophagy (and autophagy) mechanisms in the context of heart disease with an important focus on atherosclerosis, ischemic heart disease, cardiomyopathies, heart failure, hypertension, arrhythmia, congenital heart disease and peripheral vascular disease. We aim to provide a complete background on the mechanisms of action of this mitochondrial quality control process in cardiology and in cardiac surgery by also reviewing studies on the use of known compounds able to modulate mitophagy for cardioprotective purposes

Constitutive IP₃ signaling underlies the sensitivity of B-cell cancers to the Bcl-2/IP₃ receptor disruptor BIRD-2

Anti-apoptotic Bcl-2 proteins are upregulated in different cancers, including diffuse large B-cell lymphoma (DLBCL) and chronic lymphocytic leukemia (CLL), enabling survival by inhibiting pro-apoptotic Bcl-2-family members and inositol 1,4,5-trisphosphate (IP3) receptor (IP3R)-mediated Ca2+-signaling. A peptide tool (Bcl-2/IP3R Disruptor-2; BIRD-2) was developed to abrogate the interaction of Bcl-2 with IP3Rs by targeting Bcl-2′s BH4 domain. BIRD-2 triggers cell death in primary CLL cells and in DLBCL cell lines. Particularly, DLBCL cells with high levels of IP3R2 were sensitive to BIRD-2. Here, we report that BIRD-2-induced cell death in DLBCL cells does not only depend on high IP3R2-expression levels, but also on constitutive IP3 signaling, downstream of the tonically active B-cell receptor. The basal Ca2+ level in SU-DHL-4 DLBCL cells was significantly elevated due to the constitutive IP3 production. This constitutive IP3 signaling fulfilled a pro-survival role, since inhibition of phospholipase C (PLC) using U73122 (2.5 µM) caused cell death in SU-DHL-4 cells. Milder inhibition of IP3 signaling using a lower U73122 concentration (1 µM) or expression of an IP3 sponge suppressed both BIRD-2-induced Ca2+ elevation and apoptosis in SU-DHL-4 cells. Basal PLC/IP3 signaling also fulfilled a pro-survival role in other DLBCL cell lines, including Karpas 422, RI-1 and SU-DHL-6 cells, whereas PLC inhibition protected these cells against BIRD-2-evoked apoptosis. Finally, U73122 treatment also suppressed BIRD-2-induced cell death in primary CLL, both in unsupported systems and in co-cultures with CD40L-expressing fibroblasts. Thus, constitutive IP3 signaling in lymphoma and leukemia cells is not only important for cancer cell survival, but also represents a vulnerability, rendering cancer cells dependent on Bcl-2 to limit IP3R activity. BIRD-2 seems to switch constitutive IP3 signaling from pro-survival into pro-death, presenting a plausible therapeutic strategy

Data on administration of cyclosporine, nicorandil, metoprolol on reperfusion related outcomes in ST-segment Elevation Myocardial Infarction treated with percutaneous coronary intervention

Mortality and morbidity in patients with ST elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) are still high [1]. A huge amount of the myocardial damage is related to the mitochondrial events happening during reperfusion [2]. Several drugs directly and indirectly targeting mitochondria have been administered at the time of the PCI and their effect on fatal (all-cause mortality, cardiovascular (CV) death) and non fatal (hospital readmission for heart failure (HF)) outcomes have been tested showing conflicting results [3]; [4]; [5]; [6]; [7]; [8]; [9]; [10]; [11]; [12]; [13]; [14]; [15] ; [16]. Data from 15 trials have been pooled with the aim to analyze the effect of drug administration versus placebo on outcome [17]. Subgroup analysis are here analyzed: considering only randomized clinical trial (RCT) on cyclosporine or nicorandil [3]; [4]; [5]; [9]; [10] ; [11], excluding a trial on metoprolol [12] and comparing trial with follow-up length <12 months versus those with longer follow-up [3]; [4]; [5]; [6]; [7]; [8]; [9]; [10]; [11]; [12]; [13]; [14]; [15] ; [16]. This article describes data related article titled “Clinical Benefit of Drugs Targeting Mitochondrial Function as an Adjunct to Reperfusion in ST-segment Elevation Myocardial Infarction: a Meta-Analysis of Randomized Clinical Trials” [17]

Clinical benefit of drugs targeting mitochondrial function as an adjunct to reperfusion in ST-segment elevation myocardial infarction:A meta-analysis of randomized clinical trials

Aims: To perform a systematic review and meta-analysis of randomized clinical trials (RCT) comparing the effectiveness of drugs targeting mitochondrial function vs. placebo in patients with ST-segment elevation myocardial infarction (STEMI) undergoing mechanical coronary reperfusion. Methods: Inclusion criteria: RCTs enrolling STEMI patients treated with primary percutaneous coronary intervention (PCI) and comparing drugs targeting mitochondrial function vs. placebo. Odds ratios (OR) were computed from individual studies and pooled with random-effect meta-analysis. Results: Fifteen studies were identified involving 5680 patients. When compared with placebo, drugs targeting mitochondrial component/pathway were not associated with significant reduction of cardiovascular and all-cause mortality (OR 0.9, 95% CI 0.7–1.17 and OR 0.92, 95% CI 0.69–1.23, respectively). However, these agents significantly reduced hospital admission for heart failure (HF) (OR 0.64; 95% CI 0.45–0.92) and increased left ventricular ejection fraction (LVEF) (OR 1.44; 95% CI 1.15–1.82). After analysis for subgroups according to the mechanism of action, drugs with direct/selective action did not reduce any outcome. Conversely, those with indirect/unspecific action showed a significant effect on cardiovascular mortality (0.65, 95% CI 0.46–0.92), all-cause mortality (OR 0.69, 95% CI 0.52–0.92), hospital readmission for HF (OR 0.41, 95% CI 0.28–0.6) and LVEF (OR 1.49, 95% CI 1.09–2.05). Conclusions: Administration of drugs targeting mitochondrial function in STEMI patients undergoing primary PCI appear to have no effect on mortality, but may reduce hospital readmission for HF. The drugs with a broad-spectrum mechanism of action seem to be more effective in reducing adverse events

Increase of Parkin and ATG5 plasmatic levels following perinatal hypoxic‐ischemic encephalopathy

Brain injury at birth is an important cause of neurological and behavioral disorders. Hypoxic‐ischemic encephalopathy (HIE) is a critical cerebral event occurring acutely or chronically at birth with high mortality and morbidity in newborns. Therapeutic strategies for the prevention of brain damage are still unknown, and the only medical intervention for newborns with moderate‐to‐severe HIE is therapeutic hypothermia (TH). Although the neurological outcome depends on the severity of the initial insult, emerging evidence suggests that infants with mild HIE who are not treated with TH have an increased risk for neurodevelopmental impairment; in the current clinical setting, there are no specific or validated biomarkers that can be used to both correlate the severity of the hypoxic insult at birth and monitor the trend in the insult over time. The aim of this work was to examine the presence of autophagic and mitophagic proteins in bodily fluids, to increase knowledge of what, early at birth, can inform therapeutic strategies in the first hours of life. This is a prospective multicentric study carried out from April 2019 to April 2020 in eight third‐level neonatal intensive care units. All participants have been subjected to the plasma levels quantification of both Parkin (a protein involved in mitophagy) and ATG5 (involved in autophagy). These findings show that Parkin and ATG5 levels are related to hypoxic‐ischemic insult and are reliable also at birth. These observations suggest a great potential diagnostic value for Parkin evaluation in the first 6 h of life

The metabolic co-regulator PGC1α suppresses prostate cancer metastasis

Cellular transformation and cancer progression is accompanied by changes in the metabolic landscape. Master co-regulators of metabolism orchestrate the modulation of multiple metabolic pathways through transcriptional programs, and hence constitute a probabilistically parsimonious mechanism for general metabolic rewiring. Here we show that the transcriptional co-activator peroxisome proliferator-activated receptor gamma co-activator 1α (PGC1α) suppresses prostate cancer progression and metastasis. A metabolic co-regulator data mining analysis unveiled that PGC1α is downregulated in prostate cancer and associated with disease progression. Using genetically engineered mouse models and xenografts, we demonstrated that PGC1α opposes prostate cancer progression and metastasis. Mechanistically, the use of integrative metabolomics and transcriptomics revealed that PGC1α activates an oestrogen-related receptor alpha (ERRα)-dependent transcriptional program to elicit a catabolic state and metastasis suppression. Importantly, a signature based on the PGC1α–ERRα pathway exhibited prognostic potential in prostate cancer, thus uncovering the relevance of monitoring and manipulating this pathway for prostate cancer stratification and treatment

Mitochondria in Coronary Reperfusion Injury and Cancer: c subunit of FoF1-ATP synthase and Mcl-1 as potential therapeutic targets.

I mitocondri sono in grado di decodificare una grande varietà di stimoli extracellulari dando origine a innumerevoli processi fisiopatologici: dalla produzione di energia alla morte cellulare. Quando l’omeostasi mitocondriale del calcio è compromessa, possono verificarsi condizioni patologiche anche gravi come il cancro e il cosiddetto danno da riperfusione coronarica. Durante il mio dottorato, ho cercato di far luce su meccanismi attraverso i quali i mitocondri sono responsabili della sensibilizzazione di cellule tumorali (HeLa) a stimoli apoptotici calcio-dipendenti e in che modo essi possano influenzare la morte cellulare e quindi l’area infartuata finale in pazienti affetti da infarto del miocardio di tipo STEMI. Nel primo caso, sono stati condotti esperimenti utilizzando metodiche di modulazione dell’espressione genica come quella degli oligonucleotidi antisenso. Il bersaglio, la proteina Mcl-1. Il suo utilizzo ha portato ad un aumento della sintesi del prodotto terapeutico Mcl-1S e una concomitante riduzione di Mcl-1L, con conseguente aumentata sensibilità delle cellule tumorali a stimoli apoptotici. L’oligonucleotide antisenso specifico per Mcl-1 ha anche indotto iperpolarizzazione mitocondriale con un conseguente accumulo di calcio nello stesso compartimento sub-cellulare. L'elevato rapporto Mcl-1S/Mcl-1L ha comportato un significativo stato di iperfusione dell'intera rete mitocondriale, verificatosi in maniera dependente dalla proteina di fissione mitocondriale Drp1. Ho proposto il rapporto intracellulare delle due isoforme proteiche Mcl-1L/S come un nuovo fattore di regolazione delle dinamiche mitocondriali di fusione e fissione. Nella seconda parte del lavoro, lo studio in corso di sviluppo sulla subunità c dell’ATP sintasi in campioni biologici di pazienti affetti da infarto di tipo STEMI, ha suggerito che i livelli sierici circolanti della proteina sono fortemente correlati a parametri clinici quali le dimensioni dell’infarto, la risoluzione del tratto ST e lo stato clinico del paziente. Inoltre, i livelli proteici di subunità c rilevati in fibroblasti provenienti da biospia cutanea, risultano essere correlati con l'attività del mPTP e l'indice MSI del relativo paziente.Mitochondria are able to decode a variety of extracellular stimuli into greatly different intracellular actions, ranging from energy production to cell death. When mitochondrial Ca2+ homeostasis is compromised, very different pathological conditions can occur, from cancer to ischemia/reperfusion injury, depending on the cell type and pathway involved. During my Phd I tried to shed light on both mechanisms by which mitochondria are responsible for sensitizing cancer cells to Ca2+dependent apoptotic stimuli in HeLa cells and how they can influence cell death and infarct size (IS) in a STEMI-patients cohort. In the first case, performed experiments by using splice-switching antisense oligonucleotides (ASOs) specific for Mcl-1, allowed to increase the synthesis of Mcl-1S which induced a concurrent reduction of Mcl-1L, resulting in increased sensitivity of cancer cells to apoptotic stimuli. The Mcl-1 ASOs also induced mitochondrial hyperpolarization and a consequent increase in mitochondrial Ca2+ accumulation. The high Mcl-1S/L ratio correlated with significant hyperfusion of the entire mitochondrial network, which occurred in a dynamin-related protein (Drp1)–dependent manner. I propose that the Mcl-1L/S balance is a novel regulatory factor controlling the mitochondrial fusion and fission machinery. In the second part, the ongoing study on c subunit of FoF1-ATP synthase (Csub) in biological samples from STEMI patients showed that circulating Csub was strongly related to infarct size, ST-segment resolution and clinical outcome. Moreover, Csub expression found in fibroblasts from skin biopsy had a good correlation with mPTP activity values and myocardial salvage index (MSI) belonging to the same STEMI-patients

Pharmacological protection of reperfusion injury in ST-segment elevation myocardial infarction. Gone with the wind?

Primary percutaneous coronary intervention (PCI) represents the greatest progress in the treatment of ST-elevation myocardial infarction (STEMI) over the last 30 years. It reduces infarct size with an early restoration of blood flow within an ischemic myocardium. However, it is associated with a still partly mysterious paradox: reperfusion injury [1]. It is characterized by reversible mechanical dysfunction called “myocardial stunning” and microvascular obstruction or the “no reflow phenomenon” which corresponds to the presence of capillary damage, endothelial cell swelling, intraluminal thrombosis and injured cardiomyocytes. Several mediators are involved in ischemia/reperfusion injury; on one hand prolonged ischemia causes pH alterations, activation of anaerobic metabolism, dysfunction of ATPase-dependent ion transport mechanisms, intracellular calcium overload, cell swelling and finally cell death. On the other hand, after reperfusion, there is an increase of reactive oxygen species and tissue infiltration of neutrophils and pro-inflammatory cytokines with paradoxical exacerbation of the ischemic injury. Consequently, at the clinical level, reperfusion injury is associated with residual large infarct size, impaired left ventricular ejection fraction, ventricular arrhythmias and poor prognosis

Other bricks for the correct construction of the mitochondrial permeability transition pore complex

n recent years, the concept of the mitochondrial permeability transition pore (mPTP) has attracted considerable attention from researchers in the field of pathophysiology, focusing on mitochondrial function as a potential therapeutic target. Indeed, given that the mPTP is considered to be the main and final effector of cell death in various disorders, numerous and progressive efforts have been undertaken using this novel molecular target, both in clinical trials and especially in basic research. Although the exact structure of this supramolecular entity is largely unknown, studies beginning in 2013 have begun to elucidate the structure of the pore-forming component the - C subunit of the F1/FO ATP synthase